In order to meet the increase in the demand for wireless data traffic after the commercialization of 4th generation (4G) communication systems, considerable effort has been made to develop pre-5th generation (5G) communication systems or improved 5G communication systems. In order to achieve a high data transmission rate, 5G communication systems are being developed to be implemented in a band of extremely high frequency, or millimeter wave (mmWave), e.g., a band of 60 GHz. This is one reason why ‘5G communication systems’ or ‘pre-5G communication systems’ are called ‘beyond 4G network communication systems’ or ‘post long term evolution (LTE) systems.’
In order to reduce the occurrence of stray electric waves in a band of extremely high frequency energy and to increase the transmission distance of electric waves in 5G communication systems, various technologies are being explored, for example: beamforming, massive multiple-input and multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antennas, analog beam-forming, large scale antennas, etc. In order to improve system networks for 5G communication systems, various technologies have been developed, e.g., evolved small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network, device to device communication (D2D), wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), interference cancellation, etc. In addition, for 5G communication systems, other technologies have been developed, e.g., hybrid frequency-shift keying (FSK) and quadrature amplitude modulation (QAM) modulation (FQAM) and sliding window superposition coding (SWSC), as advanced coding modulation (ACM), filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), sparse code multiple access (SCMA), etc.
The Internet has evolved from a human-based connection network, where humans create and consume information, to an Internet of things (IoT) where distributed configurations, such as objects, exchange information with each other to process the information. The technology related to the IoT is starting to be combined with, for example, a technology for processing big data through connection with a cloud server, and this is called an Internet of everything (IoE) technology. In order to manifest the IoT, various technical components are required, such as, a sensing technology, wired/wireless communication and network infra technology, a service interfacing technology, a security technology, etc. In recent years, a sensor network for connecting objects, machine to machine (M2M), machine type communication (MTC), etc. have been researched. Under the IoT environment, intelligent Internet Technology (IT) services may be provided to collect and analyze data obtained from objects connected to each other and thus to create new value. As existing IT technologies are fused and combined with various industries, the IoT may also be applied within various fields, such as: smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, health care, smart home appliances, high quality medical services, etc.
To this end, various attempts have been made to apply 5G communication systems to the IoT. For example, various technologies related to sensor networks, M2M, MTC, etc., have been implemented by beam-forming, MIMO, array antenna, etc., as 5G communication technology. The application of the cloud RAN as a big data processing technology described above may be an example of a hybrid of 5G technology and IoT technology.
In order to perform data transmission, LTE systems use a plurality of carriers to simultaneously transmit signals in a broad band, and may also separate user data and control information in order to transmit the separated result on the transmission time domain.
In order to achieve high speed data transmission of wireless channels in wireless systems, orthogonal frequency division multiple access (OFDMA) or single carrier-FDMA (SC-FDMA) has been researched.
Multiple Access allocates and manages data or control information according to users to time-frequency resources, so as to prevent overlapping between them, i.e., so as to achieve orthogonality, thereby distinguishing data or control information between respective users.
In order to provide high transmission rate wireless data service in mobile communication systems, one important factor is the ability to support scalable bandwidths. For example, LTE systems can support various bandwidths, such as 20, 15, 10, 5, 3, 1.4 MHz, etc.; while LTE-advanced (LTE-A) systems can provide services in a wide range of bandwidths, up to 100 MHz, via LTE carrier aggregation.
Service providers can select one of a plurality of bandwidths via which to provide their services. There are various types of user equipment (UE) devices that can support bandwidths from a minimum of 1.4 MHz to a maximum of 20 MHz.
In general, scheduling information for data transmitted on respectively configured carriers is downlink control information (DCI) to be transmitted to UE devices. DCI may define various formats. That is, DCI may apply a DCI format determined according to whether: scheduling information is related to uplink data or downlink data; DCI is compact DCI; spatial multiplexing using multiple antennas is applied; DCI is DCI for power control; etc., and may be accordingly managed. For example, the DCI may include the following information items, and then may be transmitted.                Resource allocation type 0/1 flag: This is used to notify UE whether a resource allocation method is type 0 or type 1. Type 0 allocates resources in a unit of resource block group (RBG) by applying a bitmap. In LTE and LTE-A systems, the basic unit (default unit) for scheduling is a resource block (RB) represented by time and frequency domain resources, and RBG includes a plurality of RBs, serving as a basic unit (default unit) for scheduling in type 0. Type 1 allows a particular RB to be allocated in RBG.        Resource block assignment: This may notify UE of RBs allocated to data transmission. Resources to be represented are determined according to a system bandwidth and a resource allocating method.        Modulation and coding scheme: This notifies UE of the modulation and coding rate used for data transmission.        Hybrid automatic repeat request (HARQ) process number: This notifies UE of a processor number of HARQ.        New data indicator: It notifies UE that HARQ is transmitted from the first time or re-transmitted.        Redundancy version: This notifies UE of the redundancy version of HARQ.        Transmission power control (TPC) command for physical uplink control channel (PUCCH): This notifies UE of power control command for PUCCH.        
The DCI, which can notify UE of the information items described above, is processed by channel coding and modulation, and the processed result is transmitted to the UE through physical downlink control channel (PDCCH).
User data may also be transmitted to the UE through physical downlink shared channel (PDSCH).
When there is data to be transmitted to UE through PDSCH, the transmitter of a base station needs enough power to transmit the data. However, when there is no data to be transmitted to UE, or when there is no signal in an interval of time during which PDSCH is transmitted, except for signals such as a reference signal and a synchronization signal, transmission of the signals with sufficient power may cause the waste of transmission power.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.